Tissue sealing electrosurgery device and methods of sealing tissue

ABSTRACT

An electrosurgery medical device is enhanced with unique solution-assistance, and includes, in combination, co-operating device jaws including jaw portions for manipulating tissue, and a plurality of solution infusion openings defined and spaced along each of the jaw portions, for receiving electrolytic solution and infusing the solution onto and into tissue to be manipulated, along said jaw portions. As preferred, the device further includes at least one, and most preferably, many, longitudinal groove(s) along at least one and most preferably, both, of the jaw portions, with the solution infusion openings located in the groove or grooves. The solution is energized with RF energy and contributes to the functions and beneficial effects of the instrument. The solution exits the openings in the grooves at sufficient flow rates to separate substantially all the operative surfaces of the device from tissue, thereby substantially completely preventing adherence between the operative surfaces and tissue. The solution is further energized to a range of energy densities such that tissues to be affected are sealed against flow of blood, lymphatic fluids, air, and other bodily fluids and gases.

The present application is a continuation of U.S. Ser. No. 09/580,229,filed May 26, 2000, now U.S. Pat. No. 6,443,952 which is a divisional ofU.S. Ser. No. 08/901,890, filed Jul. 29, 1997, which application ishereby incorporated by reference, now U.S. Pat. No. 6,096,037.

BACKGROUND OF THE INVENTION

This invention relates to medical instruments, and more particularly toelectrosurgical devices, and methods of manipulating tissue as, forexample, by cutting the tissue.

DESCRIPTION OF THE RELATED ART

High-frequency alternating current was used to cut and coagulate humantissue as early as 1911. Current generators and electrode tippedinstruments then progressed such that electrosurgical instruments andcurrent generators are available in a multitude of configurations forboth open procedures and endoscopic procedures, withmicroprocessor-controlled currents typically on the order of 500 KHz.Radiofrequency (RF) catheter ablation of brain lesions began in the1960s, and RF ablation of heart tissue to control supraventriculartachyarrhythmias began in the 1980s. Thus, electrical energy, includingbut not limited to RF energy, is a known tool for a variety of effectson human tissue, including cutting, coagulating, and ablative necrosis,with and as a part of electrically conductive forceps. Bipolar andmonopolar currents are both used with electrosurgical forceps. Withmonopolar current, a grounding pad is placed under the patient. A recentexample of an electrically energized electrosurgical device is disclosedin U.S. Pat. No. 5,403,312 issued on Apr. 4, 1995 to Yates et al., andthe disclosure is incorporated by reference.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an electrosurgerytissue sealing medical device which may and also may not be a forceps.

Another object of the present invention is to provide an electrosurgerytissue sealing device such as a forceps that seals tissue by a uniqueflow of an electrolytic fluid or solution to the manipulating portionsof the device in combination with energization of the solution withelectrical energy. The effect of the solution and energy may be enhancedwith pressure. The solution is brought into contact with and infuses thetissue. The solution may include saline as well as other non-toxic andtoxic electrolytic solutions, and may be energized with RF electricalenergy. The body of the device itself may or not be energized.

The solution provides at least in part the beneficial functions andeffects of the instrument. As preferred, pressure on the tissue isapplied, and most preferably the effect of pressure is optimized, as byapplying pressure across the tissue to be effected that is substantiallyuniform.

Another object of the invention is to provide an electrosurgery medicaldevice as described, and methods of sealing tissue, in which tissues aresealed against flow of fluids including air. With the invention, forexample, lung tissue is aerostatically and hemostatically sealed, withthe tissue adjacent the sealed tissue retaining blood and air.

Another object of the invention is to provide an electrosurgery medicaldevice that may take the form of open surgery forceps of a variety ofspecific forms, or endoscopic forceps, also of a variety of forms.

A further object of the invention is to provide an electrosurgerymedical device as described, in which the electrolytic solution by whichthe instrument functions is infused from the device onto and/or into thetissue along the operative portions of the device. With and withoutapplied pressure, the solution coagulates and additionally seals tissue,as a result of being energized by RF energy, and also envelopes theoperative portions of the device in solution all during manipulation oftissue, substantially completely preventing adherence between theinstrument and tissue, substantially without flushing action.

In a principal aspect, then, the invention takes the form of an enhancedsolution-assisted electrosurgery medical device comprising, incombination, co-operating device jaws including jaw portions formanipulating tissue, and a plurality of solution infusion openingsdefined and spaced along each of the jaw portions, for receivingsolution and infusing solution onto and into the tissue along said jawportions. While the device is contemplated with and without grooves, aspreferred, the device further comprises at least one, and mostpreferably, many, longitudinal grooves along at least one and mostpreferably, both, of the jaw portions. Also most preferably, thesolution infusion openings are located on the inside faces of the jawportions, adjacent to and most preferably in the groove or grooves. Thesolution exiting the openings separates substantially all the operativesurfaces of the device from tissue, substantially completely preventingadherence between the operative surfaces and tissue. The solution alsoaids in coagulation.

Coagulation aside, the invention causes hemostasis, aerostasis, and moregenerally, “omnistasis” of substantially any and all liquids and gasesfound in tissue being treated, such as lymphatic fluids and methane, aswell as blood and air. These broader effects are understood to resultfrom such actions as shrinkage of vascalature with and withoutcoagulation, and without desiccation and carbonization.

Also as preferred, the operative portions of the device may take theform of a circular, semicircular or other regular and irregulargeometric shape, to contain and/or isolate tissue to be affected andperhaps resected. As an example, with an enclosed geometric shape suchas a circle, tissue surrounding lesions and/or tumors of the lung may beaerostatically and hemostatically sealed, resulting in an isolation ofthe lesions and/or tumors for resection. Lung function is retained. Foradaption to unique tissue geometries, the operative portions of thedevice may be malleable, to be manipulated to substantially any neededcontour. For procedures including resection, the device may include anadvanceable and retractable blade, or additional functional structuresand features.

These and other objects, advantages and features of the invention willbecome more apparent upon a reading of the detailed description ofpreferred embodiments of the invention, which follows, and reference tothe drawing which accompanies this description.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing includes a variety of figures. Like numbersrefer to like parts throughout the drawing. In the drawing:

FIG. 1 is a schematic diagram of the key elements of an electricalcircuit according to the invention;

FIG. 2 is a perspective view of an endoscopic forceps according to theinvention;

FIG. 3 is a detail view of a portion of the forceps of FIG. 2; and

FIG. 4 is a perspective view of a modification of the embodiment of FIG.2;

FIG. 5 is a second modification, of the embodiment of FIG. 4, shownpartially broken away;

FIG. 6 is a perspective view of an open surgery forceps according to theinvention;

FIG. 7 is a detail view of a portion of the forceps of FIG. 6, partiallybroken away;

FIG. 8 is a schematic view of preferred saline supply equipment for theinvention;

FIG. 9 is a perspective view of a portion of the jaws of an alternativedevice;

FIG. 10 is a perspective view similar to FIG. 9 of another alternativedevice;

FIG. 11 is a cross-sectional view along line 11—11 of FIG. 9; and

FIG. 12 is a perspective view of yet another alternative device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Electrosurgery uses electrical energy to heat tissue and cause a varietyof effects such as cutting, coagulation and ablative necrosis. The heatarises as the energy dissipates in the resistance of the tissue. Theeffect is dependent on both temperature and time. Lower temperatures forlonger times often yield the same effect as higher temperatures forshorter times. Normal body temperature is approximately 37° C. Nosignificant long-term effect is caused by temperatures in the range of37° C. to 40° C. In the range of 41° C. to 44° C., cell damage isreversible for exposure times less than several hours. In the range of45° C. to 49° C., cell damage becomes irreversible at increasingly shortintervals. The following table states expected effects at highertemperatures:

Temperature (° C.) Effect 50-69 Irreversible cell damage-ablationnecrosis.  70 Threshold temperature for shrinkage of tissue. (Somecollagen hydrogen bonds break at 60-68; those with cross-linkages breakat 75-80.) 70-99 Range of coagulation. Hemostasis due to shrinkage ofblood vessels. 100 Water boils. 100-200 Desiccation as fluid isvaporized. Dependent on the length of time during which heat is applied,carbonization may occur, and at higher temperatures, occurs quickly.

This table is not intended as a statement of scientifically preciseranges above and below which no similar effects will be found, andinstead, is intended as a statement of generally accepted values whichprovide approximations of the ranges of the stated effects. Limitationof the appended claims in accordance with this and the further detailsof this description is intended to the extent such details areincorporated in the claims, and not otherwise.

As a consequence of the foregoing effects, preferred “soft” coagulationoccurs at temperatures slightly above 70° C. Heat denatures and shrinkstissues and blood vessels, thereby leading, as desired, to control ofbleeding. Cells are generally not ruptured. “Soft” coagulation isgenerally assured with voltages below 200 peak Volts. Sparks areavoided. “Forced” coagulation can be accomplished with bursts ofelectrical energy. Electric arcs are generated. Deeper coagulation isachieved, at the cost of some carbonization and an occasional cuttingeffect. Spray coagulation is also possible. Tissue cutting occurs bydesiccation, when the concentration of electrical energy, also referredto here as energy density, is acute, and the temperature of tissue israised above 100° C.

For both coagulation and cutting by electrical energy, a sine wavewaveform is employed, with a frequency of about 500 kHz. For cutting,increasing voltage to as much as 600 peak Volts leads to higher sparkintensity which results in deeper cuts. Frequencies above 300,000 Hzavoid stimulating nerve and muscle cells, and generally assure that theeffect on tissue is substantially purely thermal.

In contrast with the RF energy tissue-cutting electrosurgery tools ofthe past, significant purposes of the present invention are to provide amechanism of avoiding desiccation of tissue at the electrode/tissueinterface and to achieve sealing of tissues. By “sealing,” the effectsof hemostasis, or arresting of bleeding; “aerostasis,” or arresting ofthe passage of air; and closure of tissues such as blood vessels againstlarger-scale passage of blood, among other effects, are intended. Morespecifically, the effect of sealing at the cellular level is a primaryfocus, as is sealing at the vascular level.

Referring to FIG. 1, key elements of a preferred electrical circuitaccording to the invention include an electrosurgical unit 10, a switch12, and electrodes 14, 16. An effect is created on tissue 18 of a body20. One electrode such as electrode 14 acts as a positive or activeelectrode, while the other such as electrode 16 acts as a negative orreturn electrode. Current flows directly from one electrode to the otherprimarily through only the tissue, as shown by arrows 22, 24, 26, 28,29. No pad is needed under the patient. This is a bipolar configuration.

Referring to FIG. 2, a forceps 30 according to the invention is anendoscopic forceps, and includes manual handles 32, 34, an elongatedshaft 36, and jaws 38, 40. The handles 32, 34 pivot together and apartand through a suitable mechanism (not shown; present in the incorporatedprior art) control the jaws 38, 40 to also pivot together and apartabout a pivot connection 42. Referring to FIG. 3, each jaw 38, 40 isformed in two parts, hinged together. The jaw 38 includes a link portion44 connected directly to the forceps shaft 36, and the jaw 40 includes alink portion 46 also connected directly to the forceps shaft 36. A jawportion 48 hingedly fastened to the jaw link portion 44 completes thejaw 38; a jaw portion 50 hingedly fastened to the jaw link portion 46completes the jaw 40.

As stated in the background of the invention, a wide variety ofalternatives to the structure described and shown in FIG. 2 arepossible. Prominent examples from those incorporated include thestructures of U.S. Pat. No. 5,403,312 (Yates et al.) issued Apr. 4,1995; U.S. Pat. No. 5,395,312 (Desai) issued Mar. 7, 1995; and U.S. Pat.No. 5,318,589 (Lichtman et al.) issued Jun. 7, 1994.

Still referring to FIG. 3, a solution supply tube 52 supplieselectrolytic solution to an electrode strip 47 along the jaw portion 48,as will be described. A solution supply tube 54 supplies electrolyticsolution to a similar strip 49 along the jaw portion 50. A wire 56electrically connects to the solution supply tube 52; a wire 58electrically connects to the solution supply tube 54. All the supplies52,54,56,58, both solution and electrical, extend from the proximal ormanual handle end of the shaft 36, and connect to solution andelectrical sources.

Referring to FIG. 4, and in a second form of a jaw, designated 140, ajaw portion 150 similar to jaw portion 50 in FIG. 3, includes alongitudinal dimension in the direction of arrow 160. A plurality oflongitudinal grooves 162 are spaced side-by-side across the inner face164 of the jaw portion 150. The grooves 162 extend the full longitudinallength of the jaw portion 150. The same is true of a mirror image jawportion, not shown. Both jaw portions are incorporated in a structure asin FIG. 3, and could be placed in substitution for jaw portions 48, 50in FIG. 3. Grooves, not shown, also preferably extend along thecorresponding jaw portions 48,50 of FIGS. 2-3. Orientations of thegrooves other than longitudinal are considered possible, within thelimit of construction and arrangement to substantially retain solutionalong the operative jaw portions.

Bodily tissues to be manipulated have a natural surface roughness. Thisroughness significantly reduces the area of contact between the forcepsjaws and manipulated tissues. Air gaps are created between conventionalsmooth-surfaced jaws and tissues. If the jaws were energized when dry,electrical resistance in the tissues would be increased, and the currentdensity and tissue temperature would be extremely high. In practice,tissue surfaces are sometimes wet in spots, and yet tissue wetness isnot controlled, such that electrical power is to be set on theassumption the inner jaw surfaces are dry. This assumption is necessaryto minimize unwanted arcing, charring and smoke.

In contrast, in a forceps according to the invention, whether the jawportions are grooved or smooth, whether the grooves are longitudinal orotherwise oriented, the jaw portions are uniquely formed of a materialsuch as hollow stainless steel needle tubing such that solution infusionopenings 166 may be and are formed in the jaw inner faces such as theinner face 164, as in FIG. 4. Further, the solution supplies 52, 54shown by example in FIG. 3 may and do open into the openings 166, tosupply solution to the openings 166. As most preferred, the openings 166are laser drilled, and have a diameter in a range centered around fourthousandths (0.004) of an inch, and most preferably in a range from twoto six thousandths (0.002-0.006) inches.

The purpose of the openings 166 is to infuse solution onto and/or intothe tissue adjacent to and otherwise in contact with the forceps jawportions inner surfaces. It is understood the openings are appropriatelyas small in diameter as described above to assure more even flow amongthe openings than would otherwise occur. Further, the openings need notbe so closely spaced as to mimic the surface roughness as tissues.Microporous surfaces are possibly acceptable, while they are also notnecessary. Infusion of fluid through the jaws is to be maintained in acontinuous flow during and throughout the application of RF energy inorder for the desired tissue effect to be achieved.

With the described structure and similar structures and methods withinthe scope of the invention, numerous advantages are obtained. Deeper andquicker coagulation is possible. The conductive solution infused ontoand into the tissues maintains relatively consistent maximal electricalcontact areas, substantially preventing hot spots and allowing higherpower than soft coagulation. Little to no arcing, cutting smoke or charis formed. Jaw and tissue surface temperatures are lower than otherwise,resulting in significantly less adhesion of tissue to jaw surfaces, andsubstantially no desiccation. One mode of coagulation may be used in theplace of the three modes soft, forced, and spray. Coagulation ispossible of even the most challenging oozing tissues such as lung, liverand spleen tissues. Coagulation is more precise, where other coagulationmodes sometimes spark to the sides and produce coagulation where notdesired.

Also, and importantly, electrosurgical cutting by desiccation may beavoided, and tissue sealing achieved. As desired, tissue sealing mayoccur alone, or be accompanied with mechanical cutting, as by aretractable and advancable blade as in U.S. Pat. No. 5,458,598, and aswith blade 1210 in FIG. 12, or otherwise. The tissue sealing itself isunderstood to occur by flow of electrolytic solution to the manipulatingportions of the forceps in combination with energization of the solutionwith electrical energy, and when included, in combination with pressureon, or compression of, the tissue. Compression of tissue is understoodto deform tissues into conditions of sealing of tissues and especiallyvascalature. Compression of tissue followed by application of solutionand energy is understood to permanently maintain compressed deformationof tissue, when present, and to shrink tissue and cause proteins to fixin place. Additional understanding of others is provided in the Yates etal. patent referenced above.

The body of the forceps itself may or not be energized. As mostpreferred, the solution primarily provides the beneficial functions andeffects of the instrument. The effectiveness and extent of the tissuesealing is a function primarily of the type of tissue being manipulated,the quantity of electrolytic solution supplied to the tissue, and thepower of the electrical energy supplied to the solution. Tissues notpreviously considered to be suitable for manipulation, as by cutting,are rendered suitable for manipulation by being sealed against flow offluids, including bodily fluids and air. With the invention, forexample, lung tissue may be cut after sealing, with the tissue adjacentthe sealed tissue retaining blood and air. Examples of the principalparameters of specific uses of the invention are provided in thefollowing table. It is understood that the combined consequences of theparameters are that energy density in the tissue to be treated is in arange to effect sealing of the tissue. However, in general, a poweroutput of 7 to 150 watts is preferred.

Fluid Quantity Power Tissue Effect 2 cc's per minute 20 watts for 30 1cm diameter hemostasis per electrode seconds vessel through the vessel 2cc's per minute 30 watts for 45 lung tissue hemostasis and per electrodeseconds aerostasis 4 cc's per minute 40 watts for 90 2 cm thicknesshemostasis per electrode seconds liver tissue

In the examples for which the table is provided, the electrolyticsolution is saline. In the first example, the device in use was a deviceas in FIG. 2, with electrodes of 16 gauge tubing, 1 cm long. The tool inuse in the second and third examples was a forceps as in FIG. 6, withjaw portions 348, 350, to be described, 4 mm wide and 2.8 cm long. Nodesiccation was observed at the tissue/electrode interface. The deviceof FIG. 2 is preferred for vessel closure.

A wide variety of the currently installed electrosurgical generatorscould and will provide proper waveforms and power levels for driving thedescribed forceps. The waveforms need only be sine waves at about 500kHz, and the power need only be about 30 or more watts. As example ofavailable generators, Valleylab generators are acceptable and widelyavailable.

The electrolytic solution supplied to the forceps need only be saline,although a variety of non-toxic and toxic electrolytic solutions arepossible. Toxic fluids may be desirable when excising undesired tissues,to prevent seeding during excision. Use of a pressure bulb is possible,as shown in FIG. 8. A flexible reservoir such as an intravenous (IV) bag410 is surrounded with a more rigid rubber bulb 412 that is pressurizedwith air through an attached squeeze bulb 414. The reservoir is filledwith solution through an injection port 416. An outflow line 418 has afilter 420 and a capillary tube flow restrictor 422 to meter flow. Aclamp or valve 424 and connector 426 are also provided. A typical flowrate is one to two (1-2) cc/min at a maximum pressure of approximatelysixteen pounds per square inch (16 psi)(52 mmHg). An example of openingdiameters, numbers, and flow rate is as follows: opening diameter, 0.16mm; number of openings, 13 per cm; and flow rate, 2 cc's per minute. Along slit has also been used and found acceptable. In this embodiment,flow rates of 0.01 to 50 cc/min are preferred.

It is understood that highly significant to the invention is the spacingof a plurality of solution openings along the jaw inner surfaces. Singleopenings as in Ohta et al., that effectively pour fluid adjacent oneportion of forceps, are generally not considered suitable or effective.Openings along outer surfaces of the jaws, opposite inner surfaces, arealso generally not considered suitable or effective.

Referring to FIGS. 4 and 5, the configurations of the most preferredsolution openings are disclosed. Referring to FIG. 5, in a jaw 240,longitudinally spaced openings 166 are rotated from those shown in FIG.4, in a jaw portion 250, to turn the openings away from most directcontact with tissues, and more carefully eliminate any unintendedplugging of the openings. Electrical insulators 268 in the form ofelongated strips extend alongside the tubes which include the openings166.

Referring to FIG. 6, open surgical forceps 330 include jaws 338, 340with jaw portions 348, 350. As with jaw portion 350 in FIG. 7, the jawportions 348, 350 include spaced solution infusion openings 166 in thecentral longitudinal groove of a plurality of grooves 162. A centralchannel 370 of both jaw portions 348, 350, as shown relative to jawportion 350 in FIG. 7, supplies solution to the openings 166 fromsolution supplies 52, 54. As with the endoscopic forceps of FIGS. 2-5,the open surgical forceps 330 benefits from the unique enhancement ofelectrosurgical functions through the infusion of electrolytic solutionsonto and into tissues through the spaced, laser drilled, solutioninfusion openings in the grooves 162.

Referring to FIGS. 9 and 10, open surgical devices 430 and 530 alsoinclude jaws 438, 440 and 538, 540, respectively. The jaw portions ofthese devices are curved, and in the case of device 430, circular, toadapt the invention to specialized surgical situations of tissuemanipulation, such as those in which fluid flow is to be terminated allaround a tissue to be isolated and resected or excised. An example ofsuch a tissue is a lesion or tumor of lung tissue. In endoscopic or opensurgery, such lesions or tumors may be encircled and/or isolated,surrounding tissue sealed, and the lesions or tumors thereafterresected. Preferably, a one centimeter margin is resected about anylesion or tumor, with the lesion or tumor. As shown, the devices 430,530 are formed of substantially square cross-section tubing, best shownin the cross-sectional drawing of FIG. 11. As most preferred, the tubingincorporates a central, depressed, cross-sectionally rectangular, andelongated groove 462 and equilaterally spaced, cross-sectionallytriangular, parallel, and elongated outer grooves 464, 465. Laserdrilled openings 466, similar to openings 166 described above, arelocated in and spaced along the central groove 462.

Alternate cross-sectional shapes of tubing may be employed, asexemplified in FIG. 12. Flatter operative, e.g., inner faces of tubingare preferred within limits of constructing and arranging the operativefaces to facilitate firm grasping and holding of tissue. Non-operativesurfaces, being less of concern, may adapt to a variety of contours fora variety of alternate reasons. Further, malleable tubing may beemployed, to permit the surgeon to shape the operative portions of theinvented devices to specific physiological situations.

The infusion of conductive solutions, referred to here also aselectrolytic solutions, simultaneously with the application of RF energyto tissues is discussed in further detail in U.S. Pat. No. 5,431,649entitled “Method and Apparatus for R-F Ablation,” in the name of PeterM. J. Mulier and Michael F. Hoey; in U.S. Pat. No. 5,609,151, entitled“Method and Apparatus for R-F Ablation,” in the name of Peter M. J.Mulier. The foregoing patents are commonly assigned to the assignee ofthe present invention, and are incorporated by reference here.

The preferred embodiments, and the processes of making and using them,are now considered to be described in such full, clear, concise andexact terms as to enable a person of skill in the art to make and usethe same. Those skilled in the art will recognize that the preferredembodiments may be altered and modified without departing from the truespirit and scope of the invention as defined in the appended claims. Forexample, if the invented device is incorporated in forceps, the forcepsmay be varied in a range from excision and cutting biopsy forceps, toendoscopic forceps, dissecting forceps, and traumatic, atraumatic andflexible endoscopic grasping forceps. The jaws may close into full andtight contact with each other, or close into spaced relationship to eachother, to accommodate tissue for purposes other than cutting. Asexpressed above, parallel spaced relationship is considered mostpreferably for uniformity of application of pressure across tissue to beaffected.

A variety of features such as jaw serrations, single acting and doubleacting jaws, closing springs, ratchet locks, fingertip rotation rings,color coding and smoke aspiration may or may not be included with thefeatures described in detail. Devices according to the invention may beconstructed and arranged to grasp, hold, fix, cut, dissect, expose,remove, extract, retrieve, and otherwise manipulate and treat organs,tissues, tissue masses, and objects. Endoscopic forceps according to theinvention may be designed to be used through a trocar. Bipolar andmonopolar currents may both be used. With monopolar current, groundingpads may be placed under patients. The described grooves may beeliminated in favor of alternative grooves.

For purposes of the appended claims, the term “manipulate” includes thedescribed functions of grasping, holding, fixing, cutting, dissecting,exposing, removing, extracting, retrieving, coagulating, ablating andotherwise manipulating or similarly treating organs, tissues, tissuemasses, and objects. Also for purposes of the appended claims, the term“tissue” includes organs, tissues, tissue masses, and objects. Furtherfor purposes of the appended claims, the term “electrical energysufficient to affect tissue” includes electrical energy sufficient toraise tissue temperature to cause non-reversible effect on tissue asdescribed above.

To particularly point out and distinctly claim the subject matterregarded as invention, the following claims conclude this specification.

We claim:
 1. An electrosurgical device for ablating tissue, the device comprising: a jaw comprising a first jaw arm and a second jaw arm, the first and second jaw arms each having a portion on an inner face for engaging tissue; an elongated, hollow tube on the inner face of at least one of the first jaw arm and the second jaw arm; the tube extending along a portion of the jaw arm and at least partially recessed within a portion of the jaw arm, the tube having a plurality of infusion openings positioned along the length of tube, the plurality of infusion openings in fluid communication with a source of an electrically conductive liquid; and an electrical conductor for conducting electrical energy to the tube.
 2. An electrosurgical device as in claim 1 wherein the infusion openings are positioned in a groove in the inner face of the jaw arm.
 3. An electrosurgical device as in claim 1 wherein the infusion openings are micropores.
 4. An electrosurgical device as in claim 1 wherein the infusion openings have diameters in a range from about 0.002 to about 0.006 inches.
 5. An electrosurgical device as in claim 1 wherein the hollow tube comprises a conductive material.
 6. An electrosurgical device as in claim 5 wherein the conductive material is metal.
 7. An electrosurgical device as in claim 6 wherein the metal is stainless steel.
 8. An electrosurgical device as in claim 1 wherein the hollow tube is recessed within an electrically insulative portion of the jaw arm.
 9. An electrosurgical device as in claim 1 wherein the inner face of the jaw arm includes one or more grooves.
 10. An electrosurgical device as in claim 1 wherein the tube is curved.
 11. An electrosurgical device as in claim 1 further comprising a handle and a mechanism connected to the handle and to the first and second jaw arms, whereby the movement of the first jaw arm in relationship to the second jaw arm may be manipulated from the handle.
 12. An electrosurgical device as in claim 11 further comprising a shaft extending from the handle to the first and second jaw arms, the shaft and jaws arms being elongated to permit endoscopic use of the device.
 13. An electrosurgical device as in claim 1 further comprising a pivot for pivoting movement of the first and second jaw arms towards each other and away from each other.
 14. An electrosurgical device as in claim 1 further comprising means for moving the first and second jaw arms in a parallel spaced relationship.
 15. An electrosurgical device as in claim 1 further comprising means for substantially uniformly compressing tissue by the portions for engaging tissue.
 16. An electrosurgical device as in claim 1 wherein both of jaw arms are curved to correspond to a contour of the tissue to be ablated.
 17. An electrosurgical device as in claim 1 wherein the curved portion has a circular contour.
 18. An electrosurgical device as in claim 1 wherein at least one portion for engaging tissue comprises a porous surface.
 19. An electrosurgical system for ablating tissue, the system comprising: a forceps, the forceps having a first jaw arm and a second jaw arm, each jaw arm including an elongated, hollow tube on the inner face of the jaw arm; the tube extending along a portion of the jaw arm and at least partially recessed within a portion of the jaw arm, the tube having a plurality of infusion openings positioned along the length of tube, and at least one electrical conductor; an electrically conductive liquid source in fluid communication with the plurality of openings; and an electrical energy source for supplying electrical energy to the electrical conductor.
 20. An electrosurgical system as in claim 19 wherein the infusion openings are positioned in a groove in the inner face of the jaw arm.
 21. An electrosurgical system as in claim 19 wherein the infusion openings are micropores.
 22. An electrosurgical system as in claim 19 wherein the infusion openings have diameters in a range from about 0.002 to about 0.006 inches.
 23. An electrosurgical system as in claim 19 wherein the hollow tube comprises metal.
 24. An electrosurgical system as in claim 23 wherein the hollow tube comprises stainless steel.
 25. An electrosurgical device as in claim 19 wherein the hollow tube is recessed within an electrically insulative portion of the jaw arm.
 26. An electrosurgical device as in claim 19 wherein the inner face of the jaw arm includes one or more grooves.
 27. An electrosurgical device as in claim 19 wherein the tube is curved.
 28. An electrosurgical system as in claim 19 wherein the electrically conductive liquid is saline solution.
 29. An electrosurgical system as in claim 19 wherein the electrically conductive liquid source supplies electrically conductive liquid at a rate in a range of about 0.01 to about 100 cc/mm.
 30. An electrosurgical system as in claim 19 wherein the electrical energy source supplies electrical energy at a power in a range of about 1 to about 200 watts.
 31. An electrosurgical system as in claim 19 wherein the electrically conductive liquid source comprises a reservoir.
 32. An electrosurgical system as in claim 31 wherein the reservoir is an IV bag.
 33. An electrosurgical system as in claim 19 wherein the electrical energy source is a RF generator.
 34. An electrosurgical device as in claim 33 wherein the RF generator provides RF energy having a sine wave waveform.
 35. An electrosurgical device as in claim 34 wherein the sine wave waveform has a frequency of about 500 kHz.
 36. A method of ablating tissue using an electrosurgical system, the method comprising: providing an electrosurgical forceps, the forceps having a first jaw arm and a second jaw arm, each jaw arm including an elongated, hollow tube on the inner face of the jaw arm; the tube extending along a portion of the jaw arm and at least partially recessed within a portion of the jaw arm, the tube having a plurality of infusion openings positioned along the length of tube; grasping an area of tissue using the electrosurgical forceps; supplying an electrically conductive fluid from an electrically conductive solution source to the plurality of infusion openings; and supplying electrical energy from an electrical energy source to the electrical conductor.
 37. A method as in claim 36 wherein the supplied electrically conductive liquid is saline solution.
 38. A method as in claim 36 wherein the electrically conductive liquid is supplied at a rate in a range of about 0.01 to about 100 cc/mm.
 39. A method as in claim 36 wherein the electrical energy is supplied at a power in a range of about 1 to about 200 watts.
 40. A method as in claim 36 wherein the electrically conductive liquid is supplied from a reservoir.
 41. A method as in claim 36 wherein the reservoir is an IV bag.
 42. A method as in claim 36 wherein the electrically conductive liquid is supplied at a rate in a range of about 0.01 to about 100 cc/mm while the electrical energy is supplied at a power in a range of about 1 to about 200 watts.
 43. A method as in claim 42 wherein the electrically conductive liquid is supplied at a rate in a range of about 2 to 8 cc/mm while the electrical energy is supplied at a power in a range of about 20 to 40 watts.
 44. A method as in claim 36 wherein the electrical energy source is a RF generator.
 45. An electrosurgical device as in claim 44 wherein the RF generator provides RF energy having a sine wave waveform.
 46. An electrosurgical device as in claim 45 wherein the sine wave waveform has a frequency of about 500 kHz. 